This invention relates to modular electronic systems, and more particularly to an interface circuit facilitating automatic determination of module presence and configuration.
As technology advances in the fields of data store, integrated circuits, circuit packaging and interconnection, available modules tend to change in size and storage capacity. For example, a new module of given size may be provided with increased data-store capacity, or a new version of a module storing a fixed amount of data may become smaller in physical size.
In the past, new-technology modules such as data-stored modules were often incompatible with existing equipment. Replacement of defective modules in existing equipment with new-technology modules was often impractical or impossible because of the need to change either the arrangement of interface signal connections, or the mounting hardware, to accommodate the new module.
Accordingly, it is an object of the invention to provide, in a modular electronic system, an improved interface between the system and modules connectable to the system.
It is another object of the invention to provide an improved dual-function interface-signal circuit.
Another object of the invention is to provide improved apparatus for automatically determining the size and configuration of connectable modules such as data-store modules in a modular electronic system.